Electrochemical control of surface wettability of poly(3-alkylthiophenes)

The effect of n-alkyl side-chain length on water contact angle with films in neutral and electrochemically doped states are studied. Increasing the side-chain from butyl to hexyl to octyl increases the contact angle of water on conjugated polymer films in both electrochemical states, but decreases the difference in angle between the states in the same film. Devices based on these films have potential application in, for example, guiding water and other liquids through microfluidic channels in lab-on-a-chip and micro-electro-mechanical (MEM) applications.